perf(test): parallelise bsoncompare corpus-b and daemon Serve() tests

bsoncompare: add t.Parallel() to the four corpus-b tests
(TestCompare_NoChange, TestAssertEqual_SelfComparePasses,
TestBuildIDMap_CorpusB, TestReadAllUnits_CorpusB). They are read-only
readers of the same file, safe for concurrent access.
Wall clock: 30 s → 8.7 s (all four overlap; max wins).

daemon: switch TestDaemon_ServeAndPing, TestDaemon_ValidateReturnsResults,
TestDaemon_NewWithSocket_ServeBindsCustom, TestClient_PingAndValidate,
and TestClient_StartIfNeeded_NoOpWhenAlive to use NewWithSocket with a
unique socket in t.TempDir(). This eliminates the default-socket conflict
that prevented parallel execution. Add t.Parallel() to all daemon tests.
Extract waitForAlive() and newTestDaemon() helpers to reduce duplication.
Wall clock: 22.7 s → 11.4 s.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

Author: claude

internal/bsoncompare/assert_test.go

@@ -19,6 +19,7 @@ func (m *mockT) Errorf(format string, args ...any) {
 }
 
 func TestAssertEqual_SelfComparePasses(t *testing.T) {
+	t.Parallel()
 	mt := &mockT{}
 	bsoncompare.AssertEqual(mt,
 		"../../testdata/corpus-b/app.mpr",

internal/bsoncompare/diff_test.go

@@ -7,6 +7,7 @@ import (
 )
 
 func TestCompare_NoChange(t *testing.T) {
+	t.Parallel()
 	diffs, err := bsoncompare.Compare(
 		"../../testdata/corpus-b/app.mpr",
 		"../../testdata/corpus-b/app.mpr",

internal/bsoncompare/idmap_test.go

@@ -7,6 +7,7 @@ import (
 )
 
 func TestBuildIDMap_CorpusB(t *testing.T) {
+	t.Parallel()
 	units, err := bsoncompare.ReadAllUnits("../../testdata/corpus-b/app.mpr")
 	if err != nil {
 		t.Fatal(err)

internal/bsoncompare/mprreader_test.go

@@ -7,6 +7,7 @@ import (
 )
 
 func TestReadAllUnits_CorpusB(t *testing.T) {
+	t.Parallel()
 	units, err := bsoncompare.ReadAllUnits("../../testdata/corpus-b/app.mpr")
 	if err != nil {
 		t.Fatalf("ReadAllUnits: %v", err)

internal/expr/daemon/client_test.go

@@ -3,6 +3,7 @@
 package daemon_test
 
 import (
+	"path/filepath"
 	"testing"
 	"time"
 
@@ -13,12 +14,14 @@ import (
 )
 
 func TestNewClient_DefaultsSocketPath(t *testing.T) {
+	t.Parallel()
 	c := daemon.NewClient(daemon.ClientOptions{MprPath: "/tmp/foo/App.mpr"})
 	assert.NotEmpty(t, c.SocketPath())
 	assert.Equal(t, daemon.SocketPath("/tmp/foo/App.mpr"), c.SocketPath())
 }
 
 func TestNewClient_ExplicitSocketPath(t *testing.T) {
+	t.Parallel()
 	c := daemon.NewClient(daemon.ClientOptions{
 		MprPath:    "/tmp/foo/App.mpr",
 		SocketPath: "/tmp/custom_42.sock",
@@ -27,25 +30,18 @@ func TestNewClient_ExplicitSocketPath(t *testing.T) {
 }
 
 func TestClient_PingAndValidate(t *testing.T) {
+	t.Parallel()
 	corpusAMPR := testutil.FindMPR(t, "CORPUS_A_MPR", "testdata/corpus-a/app.mpr")
 
-	// 直接启动 in-process daemon（无需走 StartIfNeeded → exec.Command 子进程路径），
-	// 这样 client.go 的 Ping/Validate 可以独立验证而不依赖 Task 8 的 CLI。
-	d, err := daemon.New(corpusAMPR, 5*time.Minute)
+	// Use a unique socket so this test can run in parallel with other Serve() tests.
+	sock := filepath.Join(t.TempDir(), "c.sock")
+	d, err := daemon.NewWithSocket(corpusAMPR, sock, 5*time.Minute)
 	require.NoError(t, err)
 	go func() { _ = d.Serve() }()
 	t.Cleanup(func() { _ = d.Stop() })
+	waitForAlive(t, sock)
 
-	deadline := time.Now().Add(2 * time.Second)
-	for time.Now().Before(deadline) {
-		if daemon.IsAlive(d.SocketPath()) {
-			break
-		}
-		time.Sleep(20 * time.Millisecond)
-	}
-	require.True(t, daemon.IsAlive(d.SocketPath()))
-
-	c := daemon.NewClient(daemon.ClientOptions{MprPath: corpusAMPR})
+	c := daemon.NewClient(daemon.ClientOptions{MprPath: corpusAMPR, SocketPath: sock})
 
 	// Ping
 	pr, err := c.Ping()
@@ -64,23 +60,17 @@ func TestClient_PingAndValidate(t *testing.T) {
 }
 
 func TestClient_StartIfNeeded_NoOpWhenAlive(t *testing.T) {
+	t.Parallel()
 	corpusAMPR := testutil.FindMPR(t, "CORPUS_A_MPR", "testdata/corpus-a/app.mpr")
 
-	d, err := daemon.New(corpusAMPR, 5*time.Minute)
+	sock := filepath.Join(t.TempDir(), "s.sock")
+	d, err := daemon.NewWithSocket(corpusAMPR, sock, 5*time.Minute)
 	require.NoError(t, err)
 	go func() { _ = d.Serve() }()
 	t.Cleanup(func() { _ = d.Stop() })
+	waitForAlive(t, sock)
 
-	deadline := time.Now().Add(2 * time.Second)
-	for time.Now().Before(deadline) {
-		if daemon.IsAlive(d.SocketPath()) {
-			break
-		}
-		time.Sleep(20 * time.Millisecond)
-	}
-	require.True(t, daemon.IsAlive(d.SocketPath()))
-
-	c := daemon.NewClient(daemon.ClientOptions{MprPath: corpusAMPR})
+	c := daemon.NewClient(daemon.ClientOptions{MprPath: corpusAMPR, SocketPath: sock})
 	// daemon 已活：StartIfNeeded 必须立即返回 nil，不尝试 exec.Command
 	require.NoError(t, c.StartIfNeeded())
 }

internal/expr/daemon/daemon_test.go

@@ -16,28 +16,41 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestDaemon_ServeAndPing(t *testing.T) {
-	corpusAMPR := testutil.FindMPR(t, "CORPUS_A_MPR", "testdata/corpus-a/app.mpr")
-
-	d, err := daemon.New(corpusAMPR, 5*time.Minute)
-	require.NoError(t, err)
-
-	go func() { _ = d.Serve() }()
-	t.Cleanup(func() { _ = d.Stop() })
-
-	// 等待 socket 出现 (最多 2s)
-	sockPath := daemon.SocketPath(corpusAMPR)
-	deadline := time.Now().Add(2 * time.Second)
+// waitForAlive polls the socket until it is alive or a 6-second deadline
+// expires. 6 s covers the corpus-a index build (~5 s) plus headroom.
+func waitForAlive(t *testing.T, sockPath string) {
+	t.Helper()
+	deadline := time.Now().Add(6 * time.Second)
 	for time.Now().Before(deadline) {
 		if daemon.IsAlive(sockPath) {
-			break
+			return
 		}
 		time.Sleep(20 * time.Millisecond)
 	}
-	require.True(t, daemon.IsAlive(sockPath), "socket should be alive after Serve")
+	require.True(t, daemon.IsAlive(sockPath), "daemon not alive within 6 s at %s", sockPath)
+}
+
+// newTestDaemon starts a daemon bound to a unique socket in t.TempDir()
+// so tests that call Serve() can run in parallel without socket conflicts.
+func newTestDaemon(t *testing.T, mprPath string) *daemon.Daemon {
+	t.Helper()
+	sock := filepath.Join(t.TempDir(), "d.sock")
+	d, err := daemon.NewWithSocket(mprPath, sock, 5*time.Minute)
+	require.NoError(t, err)
+	go func() { _ = d.Serve() }()
+	t.Cleanup(func() { _ = d.Stop() })
+	return d
+}
+
+func TestDaemon_ServeAndPing(t *testing.T) {
+	t.Parallel()
+	corpusAMPR := testutil.FindMPR(t, "CORPUS_A_MPR", "testdata/corpus-a/app.mpr")
+
+	d := newTestDaemon(t, corpusAMPR)
+	waitForAlive(t, d.SocketPath())
 
 	// 用空 MprPath 触发 ping 路径
-	conn, err := net.Dial("unix", sockPath)
+	conn, err := net.Dial("unix", d.SocketPath())
 	require.NoError(t, err)
 	defer conn.Close()
 	require.NoError(t, json.NewEncoder(conn).Encode(daemon.ValidateRequest{}))
@@ -51,24 +64,13 @@ func TestDaemon_ServeAndPing(t *testing.T) {
 }
 
 func TestDaemon_ValidateReturnsResults(t *testing.T) {
+	t.Parallel()
 	corpusAMPR := testutil.FindMPR(t, "CORPUS_A_MPR", "testdata/corpus-a/app.mpr")
 
-	d, err := daemon.New(corpusAMPR, 5*time.Minute)
-	require.NoError(t, err)
-	go func() { _ = d.Serve() }()
-	t.Cleanup(func() { _ = d.Stop() })
-
-	sockPath := daemon.SocketPath(corpusAMPR)
-	deadline := time.Now().Add(2 * time.Second)
-	for time.Now().Before(deadline) {
-		if daemon.IsAlive(sockPath) {
-			break
-		}
-		time.Sleep(20 * time.Millisecond)
-	}
-	require.True(t, daemon.IsAlive(sockPath))
+	d := newTestDaemon(t, corpusAMPR)
+	waitForAlive(t, d.SocketPath())
 
-	conn, err := net.Dial("unix", sockPath)
+	conn, err := net.Dial("unix", d.SocketPath())
 	require.NoError(t, err)
 	defer conn.Close()
 	require.NoError(t, json.NewEncoder(conn).Encode(daemon.ValidateRequest{
@@ -78,12 +80,11 @@ func TestDaemon_ValidateReturnsResults(t *testing.T) {
 	require.NoError(t, json.NewDecoder(conn).Decode(&resp))
 
 	assert.Empty(t, resp.Error, "no daemon-side error expected")
-	// corpus-a 项目期望至少有少量 SEM 命中（不强求精确数字）
-	// 仅验证 daemon pipeline 跑通；results 可能为 0 也可能 >0。
 	assert.NotNil(t, resp.Results)
 }
 
 func TestDaemon_SocketDirExists(t *testing.T) {
+	t.Parallel()
 	corpusAMPR := testutil.FindMPR(t, "CORPUS_A_MPR", "testdata/corpus-a/app.mpr")
 	d, err := daemon.New(corpusAMPR, 5*time.Minute)
 	require.NoError(t, err)
@@ -95,6 +96,7 @@ func TestDaemon_SocketDirExists(t *testing.T) {
 }
 
 func TestDaemon_NewWithSocket_HonoursOverride(t *testing.T) {
+	t.Parallel()
 	corpusAMPR := testutil.FindMPR(t, "CORPUS_A_MPR", "testdata/corpus-a/app.mpr")
 	custom := filepath.Join(t.TempDir(), "custom.sock")
 	d, err := daemon.NewWithSocket(corpusAMPR, custom, 5*time.Minute)
@@ -107,6 +109,7 @@ func TestDaemon_NewWithSocket_HonoursOverride(t *testing.T) {
 }
 
 func TestDaemon_NewWithSocket_EmptyFallsBackToDefault(t *testing.T) {
+	t.Parallel()
 	corpusAMPR := testutil.FindMPR(t, "CORPUS_A_MPR", "testdata/corpus-a/app.mpr")
 	d, err := daemon.NewWithSocket(corpusAMPR, "", 5*time.Minute)
 	require.NoError(t, err)
@@ -117,21 +120,13 @@ func TestDaemon_NewWithSocket_EmptyFallsBackToDefault(t *testing.T) {
 }
 
 func TestDaemon_NewWithSocket_ServeBindsCustom(t *testing.T) {
+	t.Parallel()
 	corpusAMPR := testutil.FindMPR(t, "CORPUS_A_MPR", "testdata/corpus-a/app.mpr")
-	custom := filepath.Join(t.TempDir(), "bind.sock")
-	d, err := daemon.NewWithSocket(corpusAMPR, custom, 5*time.Minute)
-	require.NoError(t, err)
-	go func() { _ = d.Serve() }()
-	t.Cleanup(func() { _ = d.Stop() })
 
-	deadline := time.Now().Add(2 * time.Second)
-	for time.Now().Before(deadline) {
-		if daemon.IsAlive(custom) {
-			break
-		}
-		time.Sleep(20 * time.Millisecond)
-	}
-	assert.True(t, daemon.IsAlive(custom),
+	d := newTestDaemon(t, corpusAMPR)
+	waitForAlive(t, d.SocketPath())
+
+	assert.True(t, daemon.IsAlive(d.SocketPath()),
 		"Serve() must bind the override socket path")
 	assert.False(t, daemon.IsAlive(daemon.SocketPath(corpusAMPR)),
 		"default SocketPath must NOT be bound when override is given")